/*

 * jerror.c

 *

 * Copyright (C) 1991-1994, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

 * For conditions of distribution and use, see the accompanying README file.

 *

 * This file contains simple error-reporting and trace-message routines.

 * These are suitable for Unix-like systems and others where writing to

 * stderr is the right thing to do.  Many applications will want to replace

 * some or all of these routines.

 *

 * These routines are used by both the compression and decompression code.

 */



/* this is not a core library module, so it doesn't define JPEG_INTERNALS */

#include "jinclude.h"

#include "jpeglib.h"

#include "jversion.h"

#include "jerror.h"



#ifndef EXIT_FAILURE		/* define exit() codes if not provided */

#define EXIT_FAILURE  1

#endif





/*

 * Create the message string table.

 * We do this from the master message list in jerror.h by re-reading

 * jerror.h with a suitable definition for macro JMESSAGE.

 * The message table is made an external symbol just in case any applications

 * want to refer to it directly.

 */



#ifdef NEED_SHORT_EXTERNAL_NAMES

#define jpeg_std_message_table	jMsgTable

#endif



#define JMESSAGE(code,string)	string ,



const char * const jpeg_std_message_table[] = {

#include "jerror.h"

  NULL

};





/*

 * Error exit handler: must not return to caller.

 *

 * Applications may override this if they want to get control back after

 * an error.  Typically one would longjmp somewhere instead of exiting.

 * The setjmp buffer can be made a private field within an expanded error

 * handler object.  Note that the info needed to generate an error message

 * is stored in the error object, so you can generate the message now or

 * later, at your convenience.

 * You should make sure that the JPEG object is cleaned up (with jpeg_abort

 * or jpeg_destroy) at some point.

 */



METHODDEF void

error_exit (j_common_ptr cinfo)

{

  /* Always display the message */

  (*cinfo->err->output_message) (cinfo);



  /* Let the memory manager delete any temp files before we die */

  jpeg_destroy(cinfo);



  exit(EXIT_FAILURE);

}





/*

 * Actual output of an error or trace message.

 * Applications may override this method to send JPEG messages somewhere

 * other than stderr.

 */



METHODDEF void

output_message (j_common_ptr cinfo)

{

  char buffer[JMSG_LENGTH_MAX];



  /* Create the message */

  (*cinfo->err->format_message) (cinfo, buffer);



  /* Send it to stderr, adding a newline */

  fprintf(stderr, "%s\n", buffer);

}





/*

 * Decide whether to emit a trace or warning message.

 * msg_level is one of:

 *   -1: recoverable corrupt-data warning, may want to abort.

 *    0: important advisory messages (always display to user).

 *    1: first level of tracing detail.

 *    2,3,...: successively more detailed tracing messages.

 * An application might override this method if it wanted to abort on warnings

 * or change the policy about which messages to display.

 */



METHODDEF void

emit_message (j_common_ptr cinfo, int msg_level)

{

  struct jpeg_error_mgr * err = cinfo->err;



  if (msg_level < 0) {

    /* It's a warning message.  Since corrupt files may generate many warnings,

     * the policy implemented here is to show only the first warning,

     * unless trace_level >= 3.

     */

    if (err->num_warnings == 0 || err->trace_level >= 3)

      (*err->output_message) (cinfo);

    /* Always count warnings in num_warnings. */

    err->num_warnings++;

  } else {

    /* It's a trace message.  Show it if trace_level >= msg_level. */

    if (err->trace_level >= msg_level)

      (*err->output_message) (cinfo);

  }

}





/*

 * Format a message string for the most recent JPEG error or message.

 * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX

 * characters.  Note that no '\n' character is added to the string.

 * Few applications should need to override this method.

 */



METHODDEF void

format_message (j_common_ptr cinfo, char * buffer)

{

  struct jpeg_error_mgr * err = cinfo->err;

  int msg_code = err->msg_code;

  const char * msgtext = NULL;

  const char * msgptr;

  char ch;

  boolean isstring;



  /* Look up message string in proper table */

  if (msg_code > 0 && msg_code <= err->last_jpeg_message) {

    msgtext = err->jpeg_message_table[msg_code];

  } else if (err->addon_message_table != NULL &&

	     msg_code >= err->first_addon_message &&

	     msg_code <= err->last_addon_message) {

    msgtext = err->addon_message_table[msg_code - err->first_addon_message];

  }



  /* Defend against bogus message number */

  if (msgtext == NULL) {

    err->msg_parm.i[0] = msg_code;

    msgtext = err->jpeg_message_table[0];

  }



  /* Check for string parameter, as indicated by %s in the message text */

  isstring = FALSE;

  msgptr = msgtext;

  while ((ch = *msgptr++) != '\0') {

    if (ch == '%') {

      if (*msgptr == 's') isstring = TRUE;

      break;

    }

  }



  /* Format the message into the passed buffer */

  if (isstring)

    sprintf(buffer, msgtext, err->msg_parm.s);

  else

    sprintf(buffer, msgtext,

	    err->msg_parm.i[0], err->msg_parm.i[1],

	    err->msg_parm.i[2], err->msg_parm.i[3],

	    err->msg_parm.i[4], err->msg_parm.i[5],

	    err->msg_parm.i[6], err->msg_parm.i[7]);

}





/*

 * Reset error state variables at start of a new image.

 * This is called during compression startup to reset trace/error

 * processing to default state, without losing any application-specific

 * method pointers.  An application might possibly want to override

 * this method if it has additional error processing state.

 */



METHODDEF void

reset_error_mgr (j_common_ptr cinfo)

{

  cinfo->err->num_warnings = 0;

  /* trace_level is not reset since it is an application-supplied parameter */

  cinfo->err->msg_code = 0;	/* may be useful as a flag for "no error" */

}





/*

 * Fill in the standard error-handling methods in a jpeg_error_mgr object.

 * Typical call is:

 *	struct jpeg_compress_struct cinfo;

 *	struct jpeg_error_mgr err;

 *

 *	cinfo.err = jpeg_std_error(&err);

 * after which the application may override some of the methods.

 */



GLOBAL struct jpeg_error_mgr *

jpeg_std_error (struct jpeg_error_mgr * err)

{

  err->error_exit = error_exit;

  err->emit_message = emit_message;

  err->output_message = output_message;

  err->format_message = format_message;

  err->reset_error_mgr = reset_error_mgr;



  err->trace_level = 0;		/* default = no tracing */

  err->num_warnings = 0;	/* no warnings emitted yet */

  err->msg_code = 0;		/* may be useful as a flag for "no error" */



  /* Initialize message table pointers */

  err->jpeg_message_table = jpeg_std_message_table;

  err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;



  err->addon_message_table = NULL;

  err->first_addon_message = 0;	/* for safety */

  err->last_addon_message = 0;



  return err;

}

